<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>案例</title>
</head>
<body>
    用户名:<input type="text" id='username'></input>
    <p></p>
    <script>
        const input = document.querySelector('input')
        const p = document.querySelector('p')

        //声明handle函数
        function handle(data){
            input.style.border = 'solid 1px #f00'
            p.innerHTML=data.msg
            console.log(data)
        }

        //绑定事件
        input.onblur = function(){
            let username=this.value
            //创建script标签
            const script =document.createElement('script')
            //设置标签的src属性
            script.src='http://127.0.0.1:8000/checkname'
            //将script插入到文档中
            document.body.appendChild(script)
        }
    </script>
</body>
</html>